Eltroxin

Levothyroxine Na

Hypothyroidism.

Adult Initially 50-100 mcg daily, adjusted at 4-6 wk intervals by 50 mcg until normal metabolism is maintained. May require doses of 100-200 mcg daily. Patient >50 yr Max: 50 mcg daily initially. Patient w/ cardiac disease 50 mcg on alternate days. May be increased by 50 mcg on alternate days at intervals of approx 4 wk. Congenital hypothyroidism Infant Starting dose: 50 mcg on alternate days w/ increments of 50 mcg on alternate days at intervals of every 2-4 wk. Juvenile myxoedema Childn >1 yr 2.5-5 mcg/kg daily.

Should be taken on an empty stomach.

Hypersensitivity. Thyrotoxicosis. Acute MI, myocarditis & pancarditis.

Patients w/ panhypopituitarism or other causes predisposing to adrenal insufficiency may cause reactions including dizziness, weakness, malaise, wt loss, hypotension & adrenal crisis. Initiate corticosteroid therapy prior to levothyroxine Na. May cause or aggravate symptoms of angina, arrhythmias, MI, cardiac failure or sudden raise in BP in patients w/ cardiac symptoms, DM or diabetes insipidus. Not for the treatment of obesity or wt loss. Patients w/ myxoedema. Decreased thyroxine absorption in patients w/ malabsorption syndromes. False low plasma conc have been observed w/ concurrent anti-inflammatory treatment eg, phenylbutazone or ASA & thyroxine therapy. Pregnancy & lactation. Elderly.

Skin rash & pruritus; increased appetite, abnormal wt loss; hyperthyroidism; abdominal cramps, nausea, vomiting, diarrhea; headache, tremors, seizure; anginal pain, cardiac arrhythmias, palpitations, tachycardia, increased BP, heart failure, MI; dyspnea; sweating, alopecia; flushing; muscle spasms, muscular weakness, premature fusion of epiphyses (in childn w/ compromised adult height); craniosynostosis (in infants); anxiety, emotional lability, nervousness, excitability, insomnia, restlessness; menstrual irregularity, impaired fertility; fatigue, heat intolerance, fever.

Increased effect of anticoagulant. May increase phenytoin levels. Enhanced metabolism w/ carbamazepine & phenytoin. Increase metabolism & excretion w/ rifampicin & barbiturates. Cardiac glycosides (dosage adjustment may be necessary). Enhanced effects of sympathomimetic agents. Accelerated TCA response. Decreased absorption w/ cholestyramine; Ca- , Al-, Mg-, Fe supplements, Al hydroxide, polystyrene sulfonates, sucralfate, lanthanum, bile acid sequestrants (eg, colestipol), anion/cation exchange resins (eg, kayexalate, sevelamer), Ca carbonate & ferrous sulphate; PPIs. Decreased intestinal absorption w/ soy-containing compd & high fibre diets. OCs; other drugs, including oestrogen, tamoxifene, clofibrate, methadone & 5-flurouracil may increase serum conc of thyroxine-binding globulin. HMG-CoA reductase inhibitors (statins) may increase thyroid hormone requirements. Drugs that may decrease serum conc of thyroxine-binding globulin, including androgens & anabolic steroids. Tyrosine kinase inhibitors (eg, imatinib & sunitinib) was associated w/ increased Levothyroxine Na dosage requirements in hypothyroid patients. Propranolol, amiodarone, lithium, iodide, oral contrast agents, propylthiouracil, glucocorticoids lower T3 level & therefore also the therapeutic effect. Sertraline can reduce serum levels of thyroxine. Levothyroxine can increase the need for insulin or oral antidiabetics in patients w/ diabetes. Potential interaction between ritonavir containing products & levothyroxine.

Thyroid Hormones

H03AA01 - levothyroxine sodium ; Belongs to the class of thyroid hormones.

Rx